The present invention relates to a charged-particle microscope device which acquires images by irradiating a sample with charged particles and a method for inspecting a sample using the charged-particle microscope device. In particular, the present invention relates to a device and a method for performing an image quality improvement process to an acquired image of a sample by means of image processing and inspecting the sample by use of the processed image.
Charged-particle microscopes, having extremely high resolution compared to optical microscopes, are widely used for clearly and sharply observing microscopic structure of the observation object. A charged-particle microscope acquires a magnified image of a sample as the object by irradiating the sample with a charged particle beam and detecting particles (charged particles (of a type identical with or different from the irradiating charged particles), electromagnetic waves or photons) emitted from or passing through the sample.
Especially in semiconductor manufacturing processes, charged-particle microscopes (scanning electron microscopes, scanning ion microscopes, scanning transmission electron microscopes, etc.) are used for inspection of semiconductor wafers, measurement of pattern dimensions, measurement of pattern shapes, etc. For these purposes, inspections (observation of semiconductor patterns and defects, detection of defects, analysis of the cause of the defects, pattern dimension measurement, etc.) are carried out using images captured by a charged-particle microscope.
Providing high-quality images is one of the most important functions of the charged-particle microscopes. As described, for example, in Patent Literature 1, Patent Literature 2 and Non-patent Literature 1, image quality improvement processes have been proposed including an edge enhancement process, an image restoration process, a noise reduction process and a contrast correction process.